Among the known herbicides there are included 1-(1,3,4-thiadiazol-2-yl)-urea derivatives, which are disclosed in Germans DT-PS Nos. 1,816,696 and 2,118,520. However, these herbicides exhibit only a very limited selectivity spectrum toward cultivated plants.
The object of the present invention is therefore the provision of herbicidal agents which will exhibit excellent activity against weeds, and at the same time a broad selectivity spectrum toward cultivated plants.